Orthodontists reproducibility and accuracy in linear and angular measurement on 2D digital and 3D CBCT radiographic examination

The use of Cone Beam Computed Tomography (CBCT) in orthodontic is evolving. Orthodontists' ability in using the CBCT radiographic images as a diagnostic aid remains to be investigated. The aim of this research is to compare the orthodontist reproducibility and accuracy in measuring distances and angles on 2D digital conventional and 3D CBCT radiographic examination. One (1) dry skull was scanned twice with Vatech digital radiographic machine and I-CAT CBCT, using guttap-percha as fiducial markers and without guttap percha. The radiographic images without guttap-percha were displayed by OsiriX software. 34 orthodontists performed cephalometric analysis on both types of radiographic images. Results: The reproducibility of anatomical landmarks between the 2D and 3D radiographic images was different on X coordinate of the A, B and Go, X and Y coordinates of the ANS, and Y coordinate of the PNS and Me. No significant differences between the linear measurement and the gold standard on the 2D and 3D radiographic images were found for Go-Me and UAFH. There were statistically significant differences between the angle measurement and the gold standard on 2D and 3D radiographic images, but not clinically significant for SNB and ANB. There were no significant differences in the accuracy of linear and angles measurement on the 2D and 3D CBCT radiographic images, except for SNA. The orthodontists' reproducibility in determining some anatomical landmarks on 2D and 3D radiographic examination is different. Orthodontists' accuracy in measuring distances and angles on 2D and 3D radiographic examination is no different.